Sun allergy is a term often used to describe a number of conditions in which an itchy red rash occurs on skin that’s been exposed to sunlight. The most common form of sun allergy is polymorphic light eruption, also known as sun poisoning.
Some people have a hereditary type of sun allergy, while others develop signs and symptoms only when triggered by another factor — such as certain types of medications or skin exposure to plants such as limes or wild parsnip.
Mild cases of sun allergy may resolve without treatment. More severe cases may require steroid creams or pills. People who have a severe sun allergy may need to take preventative measures and wear sun-protective clothing.
The appearance of skin affected by sun allergy can vary widely, depending on the disorder that’s causing the problem. Signs and symptoms may include:
*Itching or pain
*Tiny bumps that may merge into raised patches
*Scaling, crusting or bleeding
*Blisters or hives
Signs and symptoms usually occur only on skin that has been exposed to the sun and typically develops within minutes to hours after sun exposure.
Certain medications, chemicals and medical conditions can make the skin more sensitive to the sun. It isn’t clear why some people have a sun allergy and others don’t. Inherited traits may play a role.
Risk factors for having an allergic reaction to sunlight depend on your particular condition. These include:
- Race. Anyone can have a sun allergy, but certain sun allergies are most common in people of certain racial backgrounds. For example, the most common type of sun allergy (polymorphic light eruption) occurs mostly in Caucasians. A less common but more severe variety of sun allergy is most common in Native Americans.
- Exposure to certain substances. Some skin allergy symptoms are triggered when your skin is exposed to a certain substance and then to sunlight. Some common substances responsible for this type of reaction include fragrances, disinfectants and even certain chemicals used in sunscreens.
- Taking certain medications. A number of medications can make the skin sunburn more quickly — including tetracycline antibiotics, sulfa-based drugs and pain relievers such as ketoprofen.
- Having another skin condition. Having atopic dermatitis or another type of dermatitis increases your risk of having a sun allergy.
- Having relatives with a sun allergy. You’re more likely to have a sun allergy if you have a sibling or parent with a sun allergy.
If you have a sun allergy or an increased sensitivity to the sun, you can help prevent a reaction by taking these steps:
- Limit your time in the sun. Stay out of the sun between 10 a.m. and 4 p.m. when the sun is brightest.
- Avoid sudden exposure to lots of sunlight. Many people have sun allergy symptoms when they are exposed to more sunlight in the spring or summer. Gradually increase the amount of time you spend outdoors so that your skin cells have time to adapt to sunlight.
- Wear sunglasses and protective clothing. Long-sleeved shirts and wide-brimmed hats can help protect your skin from sun exposure. Avoid fabrics that are thin or have a loose weave — UV rays can pass through them.
- Apply sunscreen frequently. Use broad-spectrum sunscreen with a sun protection factor (SPF) of 30 or higher on exposed skin. Reapply sunscreen every two hours.